Can transcutaneous bilirubin levels obtained from covered skin replace serum bilirubin measurement in neonates undergoing phototherapy?

BACKGROUND

Transcutaneous bilirubinometers provide a non-invasive method to estimate total serum bilirubin (TSB) using multiwavelength reflectance. However, their accuracy during phototherapy (PT) remains controversial due to decreased dermal bilirubin.

OBJECTIVE

To assess the correlation between TSB and transcutaneous bilirubin (TcB) measured from covered and exposed skin areas before, during, and after PT.

METHODS

In this prospective study, 70 neonates undergoing PT were assessed. TcB measurements were obtained from the exposed sternum and the forehead, which were covered with an aluminum-coated radiopaque patch. TSB and TcB values were measured before PT, at 24 h during treatment, and 8 h post-treatment. The agreement between TSB and TcB values was evaluated using the intraclass correlation coefficient (ICC).

RESULTS

TcB values of covered skin showed significant correlation with TSB at all-time points (ICC = 0.665 for pre-PT, ICC = 0.520 at 24 h, and ICC = 0.537 for post-treatment). TcB values of exposed skin showed poor correlation during and after PT. Mean differences between covered TcB and TSB remained within acceptable limits (<1 mg/dL).

CONCLUSION

TcB measurements from covered skin offer a reliable, non-invasive alternative to serum bilirubin levels in neonates receiving PT, reducing the need for repeated blood draws.